Communication system, user device thereof and synchronization method thereof

Abstract

A communication system, user device thereof, and a synchronization method thereof are provided. The communication system includes a user device and a wireless network. A ciphering configuration information is transmitted to a user device. The user device and wireless network re-establishing the radio link control (RLC) entity of logical link. The user device changes to the new ciphering configuration immediately following the re-establishment of RLC entity according to the received ciphering configuration information and the wireless network changes to the new ciphering configuration.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention generally relates to a synchronization method of communication, in particular, to a synchronization method adapted to be employed in the third generation mobile communication system for decreasing the call-dropping probability thereof.[0003]2. Description of Related Art[0004]With the arrival of the information era, demands for mobile audio, data communication, and kinds of mobile service are continuously increasing. Limited communication channels and insufficient transmission speed deter the concurrent communication system to be further developed. Therefore, the third generation mobile (3G) mobile communication, capable of providing higher frequency band utilizing efficiency and faster transmission service, has been developed accordingly.[0005]FIG. 1 is a schematic diagram for illustrating a 3G mobile communication network. Referring to FIG. 1, a user equipment (UE) 10, e.g., a cellular phone or on...

AI Technical Summary

Benefits of technology

The present invention provides a synchronization method for a communication system that ensures a user device and a wireless network can synchronously transmit data with a same configuration, thus avoiding data encrypting / decrypting errors, reducing transmission failure, and decreasing call-dropping probability. The synchronization method includes transmitting a RRC re-configuration message containing ciphering configuration information to the user device, re-establishing the radio link control (RLC) entity of logical link, changing to the new ciphering configuration, and resuming the transmission of electronic information. The invention also provides a user device and a communication system that can synchronize data transmission and reduce transmission failure.

Problems solved by technology

Limited communication channels and insufficient transmission speed deter the concurrent communication system to be further developed.

However, the 3G mobile communication standard does not clearly define when the UTRAN should use its corresponding new ciphering configuration.

Unfortunately, if the UTRAN has already used the new ciphering configuration to receive the measurement report, the UE and the UTRAN is unsynchronized, thus causing incorrectly data encrypting / decrypting of the two parties.

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